Barriers to typhoid fever vaccine access in endemic countries.

Typhoid vaccines have been available as a means of disease control and prevention since 1896; however, their use as a routine tool for disease prevention in endemic settings has been hampered because of: 1) insufficient data on disease burden particularly regarding the lack of health care access in the poorest communities affected by typhoid; 2) limitations of the typhoid vaccine, such as shorter duration of protection, moderate efficacy in young children, and no efficacy for infants; 3) inadequate evidence on potential economic benefits when used for a larger population; 4) neglect in favor of alternative interventions that require massive infrastructure; 5) no financial support or commitment regarding vaccine delivery cost; 6) ambivalence about whether to invest in water and sanitation hygiene versus the vaccine; and 7) clarity on global policy for country adoption. If current typhoid-protein conjugate vaccines live up to their promise of higher efficacy, longer duration of protection, and efficacy in young children, typhoid vaccine use will be a critical component of short- and medium-term disease control strategies. Typhoid control could be accelerated if the global framework includes plans for accelerated introduction of the conjugate typhoid vaccine in developing countries.